On 10/9/05 5:17 PM, in article
,
" wrote:

Have you watched the AGC voltage as you tune across the band? I suspect the
AGC is reducing the IF gain when you tune through the mid-band, due to a
stray oscillation. Could be caused by a bad capacitor on the AGC line. A
scope should show it.

The AGC seems to be working, since the reception is good on a weak
station near the lower end of the band. I can't imagine the AGC would
work at some points in the dial and not at others.

But I can imagine an IF oscillation at some part of the BC spectrum and not
at others - been there, fixed that.


I did manage to get good reception in the middle band by adding another
antenna loopstick and capacitor. I used a few turns from the external
loopstick to couple the signal into the radio main loopstick with
another few turns.

Two loopsticks works better than one, but they won't both fit into the
same box.

-Bill


Another thought is that someone screwed up the local oscillator, and it's
operating at 2x the I.F., low. This would prevent correct tuning of the
loop's trimmer.